Math Help ( Hey, I'm new to this stuff ) Thought it was a simple multiplication problem

Gentleman is selling batteries as reads:
$58.20 for 28 = 3.7v 2400mah batteries.
Enough to make a 25.9v 9.6ah pack that works with the EZip 24v controller!

I figured he arrived at his figures by 28 X 3.7 for the voltage and 28 X 2.4 for the amphours. I was way wrong.. Can someone explain, how he arrived at 25.9 Volts and 9.6ah?
Thanks, I'm new to all this and just trying to learn.